PURPOSE: To demonstrate how an electrostatic smoke precipitator works.

DESCRIPTION: A small fan sucks smoke from a cigarette into a transparent chamber which is positioned on the overhead projector. When the Van de Graaff voltage is impressed across the long bar electrodes inside the tube, it causes the smoke particles to become electrostatically charged and the electric field between the two electrodes immediately sweeps the smoke aside, clearing the air.

The photographs below show the cavity filled with smoke (left) and after the Van de Graaff has been ON about ten seconds (right).

SUGGESTIONS: Pictures with the equipment show how it should be assembled.

REFERENCES: (PIRA 5B30.60)

EQUIPMENT: Van de Graaff generator, electrostatic precipitator chamber, cigarettes and matches, small air blower and hoses, with overhead projector; also PICTURES to show assembly details.

SETUP TIME: 5 min.